Changing server running Azure AD Connect - Compare report is listing all mydomain.com attributes changing to mydomain.onmicrosoft.com

I am retiring an old server and setting up the Azure AD Connect on a new 2019 Server. I have been running Azure AD Connect for a couple of years, after upgrading from DirSync. 

I set up the initial config on the new server and have it on staging mode. As suggested, I ran the AADConnectConfigDocumenter to compare the changes. All instances that list our verified domain mydomain.com - AAD are listed as being replaced by mydomain.onmicrosoft.com - AAD.

I can not see anywhere to have it retain the original value.

Thanks for any help,

Tony